1. The Field of the Invention
This invention relates to mechanical apparatus for operating on three-dimensional workpieces and, more particularly, to novel apparatus for operating on three-dimensional workpieces wherein the working implement is easily manipulated to perform both curvilinear and rectilinear operations.
2. The Prior Art
During recent years, it has become increasingly common to use various machines and mechanical devices to perform a variety of industrial manufacture and design operations. Notably, many of the devices which are currently in use are capable of quickly performing quite complex operations. As a result, the use of such devices has greatly increased the speed and accuracy with which many phases of industrial production may be completed. Moreover, with various types of central processing units, such as microprocessors, becoming more inexpensive and readily available, it has further become quite common to eliminate the need for a human operator in some production phases by controlling the operation of the above-mentioned devices with computer software. Such a use of computers can, of course, further enhance the speed and accuracy of the devices and provide substantial savings in time and money to both industry and consumers.
One general type of device which is frequently employed in industrial applications is a device which is capable of performing one or more manufacture or design operations on a three-dimensional workpiece. Such devices include, for example, mechanical devices which are used to machine or mill a three-dimensional object to a desired shape. Such devices also include assembly devices for placing individual components onto a three-dimensional structure or housing.
Of course, one important requirement for such devices is that they be able to contact or reach all of the relevant portions of the three-dimensional workpiece being operated upon. Hence, these devices typically include a working implement, together with structure designed to move the implement relative to a workpiece. The devices generally also include some structure for moving the workpiece relative to the implement.
One of the most common types of such prior art devices comprises a working implement which is connected to structure for moving the implement in two substantially perpendicular, linear directions. In addition, these devices further include structure for moving the workpiece in a third linear direction which is substantially perpendicular to both of the directions in which the implement may be moved.
Prior art devices of this type may, for example, comprise a working implement which is slidably maintained on a substantially horizontal, linear track, the horizontal track being further slidably connected to two substantially vertical, linear tracks. Thus, the implement may be selectively positioned within a substantially vertical plane by appropriately positioning both the implement along the horizontal track and the horizontal track along the two vertical tracks. Such prior art devices further include a mechanism for selectively translating the workpiece beneath the horizontal track in a substantially horizontal direction, thereby permitting the working implement to selectively operate on various portions of the workpiece.
Another type of prior art device for operating on a three-dimensional workpiece includes structure for providing an arcuate movement of the working implement with respect to the workpiece. Such devices are typically configured so as to be substantially identical to the prior art devices described above, except that such devices include an arcuate track in place of the above-described horizontal, linear track. Hence, in this second type of prior art device, the working implement may be moved both vertically and arcuately with respect to the workpiece being operated upon.
While the prior art devices mentioned above are capable of performing a variety of operations on three-dimensional workpieces, such prior art devices have a number of significant drawbacks and disadvantages. First, the prior art devices are not well adapted to moving a working implement in a curvilinear direction.
It will be readily appreciated that the operations to be performed by the above-described prior art devices are generally defined (due to the structure of such devices) in terms of a cartesian coordinate system (that is, a coordinate system wherein every point in three-dimensional space is defined by its position relative to three mutually perpendicular axes). In the first type of prior art device described above, for example, a point at which the implement is to operate on a workpiece is structurally defined by the vertical position of the horizontal track, the postion of the implement along the horizontal track, and the position of the workpiece along a substantially horizontal axis which passes beneath the horizontal track. Similarly, a point at which the second type of prior art device mentioned above is to operate on a workpiece is structurally defined by the vertical position of the arcuate track, the position of the implement along the arcuate track, and the position of the workpiece along a substantially horizontal axis which passes beneath the arcuate track. Thus, notwithstanding the arcuate movement of the implement in the second type of prior art device described above, the operations of such device are still structurally defined in terms of a basically cartesian-type coordinate system.
As a result of this structurally-required cartesian coordinate definition of the operations to be performed by the prior art devices, it is often quite difficult to accurately control the prior art devices so as to cause the working implement to follow a selected curvilinear path. This is due, in large part, to the fact many of the cartesian coordinate definitions of curvilinear surfaces are quite complex. Consequently, even when the prior art devices are controlled by a suitable central processing unit, substantial programming may be required in order to adequately define a desired curvilinear movement. Hence, it may, for example, be very difficult to use the prior art devices to machine or mill a workpiece to a desired curvilinear shape. In this regard, it should be noted that most industrial designs include at least one curvilinear edge or surface.
In addition to the foregoing difficulties relating to curvilinear movement, the prior art devices are also generally incapable of approaching a workpiece from various skew or angular directions. Significantly, such an angular approach to a workpiece is quite often preferred in design and manufacture applications, such as, for example, when attaching or assembling component parts to a workpiece or when forming one or more holes or cavities in a workpiece. Thus, for example, if numerous holes are to be drilled in a workpiece, the prior art devices may be unable to drill holes which are not substantially parallel to one another without the workpiece being successively manually realigned between drillings.
Further, the prior art devices are also typically complex, and they may require frequent adjustment and maintenance. For example, the two vertical tracks of the prior art devices, which are used for adjusting the vertical position of the implement, must be accurately synchronized and controlled such that the horizontal or arcuate track is continuously maintained in the proper orientation. Notably, if one side of the horizontal or arcuate track is moved vertically farther than the other side, the prior art devices will need to be serviced and properly adjusted before they can again accurately perform a desired operation. This, of course, significantly increases the cost of using the prior art devices in industry.
Accordingly, it would be an improvement in the art to provide an apparatus for operating on a three-dimensional workpiece wherein the working implement is easily adapted to curvilinear motion. It would also be an improvement in the art to provide an apparatus for operating on a three-dimensional workpiece which is capable of approaching the workpiece from virtually any direction. In addition, it would be an improvement in the art to provide an apparatus for operating on a three-dimensional workpiece which does not require frequent adjustment and maintenance. Further, it would be an improvement in the art to provide an apparatus for operating on a three-dimensional workpiece which may be readily controlled by a central processing unit to perform a wide variety of operations and movements. Such apparatus are disclosed and claimed herein.